2.0 Analysis 2.1 Flight Path 2.2 Accident Sequence 2.3 Engine and Propeller Status Because of the range of propeller pitch change possible with the start lock engaged, the pilot's pre-flight check might not reveal the left engine's stuck start lock condition. 2.4 Aircraft Performance The airspeed which the pilot reportedly maintained after take-off, 115 knots, was 18 knots higher than the emergency single-engine climb speed listed in the POH. Because maximum climb performance is available only at the best single-engine rate of climb airspeed (94knotsunder the occurrence conditions), flying at an airspeed above 94 knots reduces the aircraft's available climb performance. Both engines were producing power, but, because the aircraft's climb angle was shallow, much of the engine power was initially converted to airspeed. Because the left engine was likely on its start locks, the increasing airspeed probably allowed the left engine rpm to increase to the point where some of its power was absorbed by propeller drag and not converted to thrust. The increasing rpm presented the pilot with an indication of a malfunction in one of the aircraft's powerplants. Because the cockpit indications of the malfunction were subtle, and propeller overspeed on take-off is difficult to simulate in training, the pilot probably became task saturated and was unable to readily resolve the situation. 2.5 Crew Issues The engine overspeed emergency faced by the pilot just after take-off was subtle and difficult to analyze, because the engine sounds and cockpit and engine indications would not have been as dramatic as those of an engine failure. Because of the limited thrust still being produced by the left engine, the rudder pressure required to maintain directional control would not have been as great as the pilot would have experienced during engine failure demonstrations during his training. As well, the pilot's elevator trim setting procedure required that he apply a slight amount of back pressure to the controls to maintain level flight. This may have added to the pilot's workload during the occurrence. Manufacturer's flight test data indicate that if the pilot had maintained his reported airspeed of 115 knots and wings-level, 9nose-up attitude, the aircraft should have climbed. However, the aircraft turned, and descended and struck the lake's surface in a different attitude. The pilot's reported perceptions, therefore, differ significantly from the physical evidence. Shortly after take-off, the pilot was confronted with a confusing aircraft emergency under adverse operational and environmental conditions. In this situation, the difference between the pilot's perceptions of the flight and reality indicate that the pilot probably became overloaded and his attention became channelized, and he was unable to prevent the aircraft from striking the surface. 2.6 Patient Restraint The patient's one restraining strap, which was part of the stretcher accompanying her from the nursing station, was insufficient to secure her to the stretcher during the impact sequence. Because Transport Canada does not consider patient stretchers to be part of the aircraft in which they are used, they are not regulated, and neither their materials nor their construction are required to conform to aircraft standards. 2.7 MEDEVAC Standards A number of provinces have standards for the operation of MEDEVAC flights, but the standards are only selectively enforced. Because most aviation is federally regulated, provinces have difficulty enforcing their regulations when the MEDEVAC flight is not arranged by a provincial agency. Because many MEDEVAC flights from remote areas are arranged by a federal agency, provincial regulations governing MEDEVAC flights are often not observed. 3.0 Conclusions 3.1 Findings The aircraft was airborne for about 30 seconds after departure from runway 34 at Wollaston Lake airport and, during that time, completed a left turn of about 70. It is likely that the sparks and electrical arcing sounds and smells reported by a passenger in the aircraft occurred during, rather than before, the impact sequence. The pilot did not complete a PPC on the accident aircraft type within the 12 months before the occurrence, but Transport Canada reportedly advised the operator verbally that the pilot's PPC would continue in effect. The left propeller probably became fixed at the start lock position during the take-off acceleration phase, and went into an overspeed condition as the airspeed increased after lift-off. In the overspeed condition, some of the left engine's power was absorbed by propeller drag and was not converted to thrust. The cockpit indications of a propeller overspeed at take-off cannot readily be simulated in training, and are more subtle than those of an engine failure. The pilot probably became task saturated while attempting to determine the cause of the propeller overspeed, and his attention became channelized. The pilot did not provide a pre-flight briefing to the passengers before take-off. The operator's method of securing the stretcher to the aircraft, though unapproved, did not contribute to the patient's injuries. The restraining strap on the stretcher provided for the patient was insufficient to secure her to the stretcher during the impact sequence. The design and security of stretchers used in aircraft are not regulated by TransportCanada, and are not required to conform to aircraft standards. The company operations manual and company training programs contained no direction as to air ambulance operational procedures. There are no federal aviation standards as to aircraft, equipment, or personnel training specifically for the operation of MEDEVAC flights. Provincial regulations covering MEDEVAC operations are difficult to enforce where a MEDEVAC flight is not arranged by a provincial agency. 3.2 Causes 4.0 Safety Action 4.1 Action Taken During this investigation, it became evident that the Air Navigation Order (ANO) concerning the installation of a stretcher, incubator, or similar device in an aircraft (ANO Series II, No. 2, subsection 4(2)) was open to different interpretations. The ambiguity could have resulted in the approval of an installation which negated the airworthiness of both the device (e.g.,stretcher) and patient restraint. This shortfall has been redressed by Canadian Aviation Regulations (CAR) subsection 605.23, which states that each person carried on a stretcher, in an incubator, or other similar device must be provided with a restraint system. Such a restraint system, under the provisions of CAR 605.06, Aircraft Equipment Standards and Serviceability, must meet applicable standards of airworthiness (i.e., the equipment and its installation must be approved by Transport Canada). Additionally, Transport Canada (TC) has taken action to update its air ambulance-related publications (Guide to Air Ambulance Operations, TP 10839E and Stretcher Installation in Aircraft, ASI 32) to reflect the changes brought about by the introduction of the CARs. 4.1.2 Dissemination of Information 4.2 Action Required The term air ambulance operations refers to the transport of medical patients by air. The missions can range from a straightforward patient transfer to an emergency medical evacuation (MEDEVAC). At present, air ambulance operations are considered by TC to be a commercial air service and as such are governed by Part VII of the CARs. The granting of an Air Operator Certificate, which allows for the transport of fare-paying passengers, also permits the operator to adapt the operation for an air ambulance service. The CARs contain no specific reference to or standards with respect to the conduct of air ambulance operations, and conducting such a service does not require an amendment to the Operations Specification. As such, TC might not be aware that an operator is conducting an air ambulance service and, therefore, might not include aspects specific to air ambulance operations in any TC audit and surveillance of the operator. TC currently relies on operators to voluntarily make the necessary changes to aircrew training and operational procedures, and to seek TC airworthiness approval of equipment installations before offering air ambulance service to the public. However, in this occurrence, the operator was conducting an air ambulance service without a TC-approved stretcher installation, additional aircrew training, and amended manuals to reflect specific air ambulance procedures. As noted earlier, several provinces have set standards for aircraft, passenger restraints, aero-medical equipment, ground facilities, and personnel training. However, these standards are reportedly difficult to enforce in situations where the flight is arranged or paid for by an organization other than an agency of the respective provincial government. As recognized in Transport Canada's air ambulance guidance documents and in the efforts by some provincial governments to regulate the air ambulance services in their respective provinces, the provision of consistently safe air ambulance service requires equipment, training, and procedures considerably different from those required for regular passenger-carrying operations. The Board understands that in other occurrences (e.g.,TSBA89O0280), patient safety has been compromised by inadequate protective measures (vis--vis those afforded a normal passenger). Notwithstanding measures taken by some provinces to enhance patient safety in air ambulance operations, the Board believes that a consistent level of safety across Canada will not be attained through voluntary measures. Crews and patients will remain at risk to the extent that patients are transported with inappropriate equipment or by crews that have not been adequately trained in meeting the special needs of non-ambulatory medical patients. Therefore, the Board recommends that: The Department of Transport require all air carriers operating air ambulance services in the course of their business to provide the equipment, procedures, and crew training necessary to ensure a level of safety for patients consistent with that provided by commercial air services to fare-paying passengers. 4.3 Safety Concern In a previous occurrence report involving a MEDEVAC, the Board wrote: Between 1976 and 1994, there were 38 occurrences involving aircraft engaged in air ambulance or medical evacuation flights. Fifteen of these accidents took place in Canada's designated North.... Twenty-one of the MEDEVAC accidents occurred during VFR flights, and 18 occurred on dark nights (i.e. notwithstanding reported flight visibility conditions, the absence of ambient lighting, either from surrounding built-up areas or from the moon, created extra problems for conducting flight by visual outside reference). Twelve of the 38 MEDEVAC accidents were CFIT [controlled flight into terrain] accidents, which occurred at night. This accident at Kuujjuaq underlines the Board's earlier concern in that MEDEVAC flights may be conducted on an ad hoc basis without operators having met any particular standards for conducting such flights in the harsh physical environment of the Arctic. (TSB A94Q0182) This accident at Wollaston Lake also raises questions as to the adequacy of the regulatory oversight for the maintenance of safety standards for air ambulance operations. Although this accident involved a commercial air service, approximately 12% of air ambulance occurrences involve State-owned aircraft, usually on behalf of a provincial government. The Board has previously made observations on the different level of safety that is required for such state-owned operations, vis vis that required for commercial air services. For example, a recent Board report (TSB A93Q0245) stated: ...when passengers are regularly carried on state aircraft, it is reasonable for these passengers to expect that the aircraft and the aircrew involved in state operations are subject to the same regulatory requirements as commercial carriers.... Therefore the Board recommends that: The Department of Transport require that the operators of state aircraft be subject to regulatory overview, as practicable, equivalent to that of similar commercial operations. In essence, Transport Canada rejected this recommendation. Although the Board finds no particular fault with state-owned air ambulance services at this time, it remains concerned about continuing disparities between state and commercial operations in the levels of safety offered. The Board is not making a further recommendation in this regard as a result of this accident involving a commercial aircraft. Nevertheless, it is for consideration that any differences in safety standards between state and commercial air services with respect to the conduct of air ambulance operations should be eliminated.